Controlled interfacial assembly and transfer of brushlike copolymer films

The self-assembly and compression of polybutadiene-bpoly(ethylene oxide) (PBd-PEO) at the air/water interface enables control over surface density, height, and film structure. Interfacial transfer was performed by a combination of Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) techniques, resulting in monolayer and bilayer films. Ellipsometry and wettability results were used to characterize the efficiency of transfer and to determine the properties of the resulting films, confirming a brushlike monolayer. Importantly, a high surface density is essential to obtain the desired film structure (i.e. a dense brush) and surface properties. The films were challenged by adsorption of fibrinogen, and the results are consistent with the notion of a PEO-enriched, and protein-repellant, bilayer surface. Such a bilayer film provides an opportunity for a tunable biomaterial interface to probe cell-surface interactions.